Camera Optical Lens

ABSTRACT

The present disclosure discloses a camera optical lens. The camera optical lens includes, in an order from an object side to an image side, a first lens, a second lens, a third lens, and a fourth lens. The first lens is made of plastic material, the second lens is made of plastic material, the third lens is made of plastic material, and the fourth lens is made of plastic material. The camera optical lens further satisfies specific conditions.

FIELD OF THE PRESENT DISCLOSURE

The present disclosure relates to optical lens, in particular to acamera optical lens suitable for handheld devices such as smart phonesand digital cameras and imaging devices.

DESCRIPTION OF RELATED ART

With the emergence of smart phones in recent years, the demand forminiature camera lens is increasing day by day, but the photosensitivedevices of general camera lens are no other than Charge Coupled Device(CCD) or Complementary metal-Oxide Semiconductor Sensor (CMOS sensor),and as the progress of the semiconductor manufacturing technology makesthe pixel size of the photosensitive devices shrink, coupled with thecurrent development trend of electronic products being that theirfunctions should be better and their shape should be thin and small,miniature camera lens with good imaging quality therefor has become amainstream in the market. In order to obtain better imaging quality, thelens that is traditionally equipped in mobile phone cameras adopts athree-piece or four-piece lens structure. And, with the development oftechnology and the increase of the diverse demands of users, and underthis circumstances that the pixel area of photosensitive devices isshrinking steadily and the requirement of the system for the imagingquality is improving constantly, the five-piece, six-piece andseven-piece lens structure gradually appear in lens design. There is anurgent need for ultra-thin wide-angle camera lenses which have goodoptical characteristics and the chromatic aberration of which is fullycorrected.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the exemplary embodiments can be better understood withreference to the following drawings. The components in the drawing arenot necessarily drawn to scale, the emphasis instead being placed uponclearly illustrating the principles of the present disclosure.

FIG. 1 is a schematic diagram of a camera optical lens in accordancewith embodiment of the present invention;

FIG. 2 shows the longitudinal aberration of the camera optical lensshown in FIG. 1;

FIG. 3 shows the lateral color of the camera optical lens shown in FIG.1;

FIG. 4 presents a schematic diagram of the field curvature anddistortion of the camera optical lens shown in FIG. 1;

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The present disclosure will hereinafter be described in detail withreference to several exemplary embodiments. To make the technicalproblems to be solved, technical solutions and beneficial effects of thepresent disclosure more apparent, the present disclosure is described infurther detail together with the figure and the embodiments. It shouldbe understood the specific embodiments described hereby is only toexplain the disclosure, not intended to limit the disclosure.

As referring to FIG. 1, the present invention provides a camera opticallens 10. FIG. 1 shows the camera optical lens 10 of embodiment of thepresent invention, the camera optical lens 10 comprises 4 lenses.Specifically, from the object side to the image side, the camera opticallens 10 comprises in sequence: a first lens L1, a second lens L2, athird lens L3, and a fourth lens L4. The first lens L1 has a positiverefractive power, the second lens L2 has a negative refractive power,the third lens L3 has a positive refractive power, the fourth lens L4has a negative refractive power. Optical element like optical filter GFcan be arranged between the fourth lens L4 and the image surface Si. Thefirst lens L1 is made of plastic material, the second lens L2 is made ofplastic material, the third lens L3 is made of plastic material, and thefourth lens L4 is made of plastic material. The first lens L1 is aFresnel lens, the second lens, the third lens, and the fourth lens areeven aspheric surface lenses, wherein the first lens are configured tobe Fresnel lenses which can reduce the cost.

The first lens L1 has a positive refractive power with a convex imageside surface relative to the proximal axis, the second lens L2 has anegative refractive power with a convex object side surface relative tothe proximal axis and a concave image side surface relative to theproximal axis, the third lens L3 has a positive refractive power with aconcave object side surface relative to the proximal axis and a conveximage side surface relative to the proximal axis , the fourth lens L4has a negative refractive power with a convex object side surfacerelative to the proximal axis and a concave image side surface relativeto the proximal axis.

Here, the focal length of the whole camera optical lens 10 is defined asf, the focal length of the first lens L1 is defined as f1, the focallength of the third lens L3 is defined as f3, the focal length of thefourth lens L4 is defined as f4. Here the following condition shouldsatisfied: 0.7<f1/f<1.25, −2.5<f2/f<−1.5, 0.60<f3/f<1.1,−1.5<f4/f<−0.7.

When the focal length of the camera optical lens 10 of the presentinvention, the focal length of each lens satisfy the above conditions,the refractive power configuration of each lens can becontrolled/adjusted which can ensure the imaging quality and reducingthe length of the system. Therefore, the imaging performance of thesystem has better imaging quality, more suitable for high-pixel of theportable camera.

In this embodiment, the focal length of the first lens L1 is defined asf1, the focal length of the second lens L2 is defined as f2, the focallength of the third lens L3 is defined as f3, and the focal length ofthe fourth lens L4 is defined as f4. Here the following condition shouldsatisfied: 2≤f1≤5,−5≤f2≤−3,1.5≤f3≤3,−5≤f4≤−2. The unit of distance,radius and center thickness is mm With such design, the total opticallength TTL of the whole camera optical lens 10 can be made as short aspossible, thus the miniaturization characteristics can be maintained.

In this embodiment, the total optical length TTL of the camera opticallens and the image height IH satisfy the following condition:IH/TTL>0.62.

In this embodiment, the total optical length TTL of the camera opticallens 10 is less than or equal to 3.6 mm the focal length of the cameraoptical lens 10 can be implemented the miniaturization characteristics.

In this embodiment, each lens of the camera optical lens adopts the Abbenumber difference material, which can effectively correct colordifference of the system and satisfy the color difference of the systemΔV>30.

Further, in this embodiment, the refractive power of the first lens L1is defined as n1, the refractive power of the second lens L2 is definedas n2, the refractive power of the third lens L3 is defined as n3, andthe refractive power of the fourth lens L4 is defined as n4, thefollowing condition shall be satisfied, 1.55≤n1≤1.65, 1.6≤n2≤1.67,1.50≤n3≤1.55, 1.6≤n4≤1.67. Such design enables the lenses made fromdifferent optical materials to match each other better, and furtherenables the camera lens 10 to perform better imaging quality.

In addition, in this embodiment, set the first lens of the cameraoptical lens to the Fresnel surface, which can control more variables toreduce the effective “thickness” of each lens, thereby reducing thenumber of lenses, and therefore, the present invention can beeffectively reduced the total length of the camera optical lens.

Preferably, inflexion points and/or arrest points can also be arrangedon the object side surface and/or image side surface of the lens, sothat the demand for high quality imaging can be satisfied, thedescription below can be referred for specific implementable scheme.

The design information of the camera optical lens 10 in this embodimentof the present invention is shown in the tables 1 and 2.

TABLE 1 focal length (mm) f 2.618 f1 2.374 f2 −4.599 f3 2.187 f4 −2.698f12 3.8925 f123 2

Where:

the meaning of the various symbols is as follows.

f: the focal length of the camera optical lens;

f1: the focal length of the first lens;

f2: the focal length of the second lens;

f3: the focal length of the third lens;

f4: the focal length of the fourth lens;

f12: the combined focal length of the first lens and the second lens;

f123: the combined focal length of the first lens, the second lens, andthe third lens;

TABLE 2 Curvature Thickness/Distance Abbe radius (R) (d) Refractivenumber (mm) (mm) power (nd) (νd) St St ∞ d0= −0.013 L1 R1 3.133 d1=0.680 nd1 1.54 ν1 56.12 R2 −2.040 d2= 0.029 L2 R3 3.407 d3= 0.311 nd21.64 ν2 22.41 R4 1.532 d4= 0.491 L3 R5 −1.923 d5= 0.597 nd3 1.54 ν356.12 R6 −0.817 d6= 0.065 L4 R7 1.360 d7= 0.402 nd4 1.54 ν4 56.12 R80.633 d8= 0.500 Glass R9 ∞ d9= 0.210 ndg 1.52 νg 64.17  R10 ∞  d10=0.514

In which, R1 and R2 represent respectively the object side surface andimage side surface of the first lens L1, R3 and R4 representrespectively the object side surface and image side surface of thesecond lens L2, R5 and R6 represent respectively the object side surfaceand image side surface of the third lens L3, R7 and R8 representrespectively the object side surface and image side surface of thefourth lens L4, R9 and R10 represent respectively the object sidesurface and image side surface of the optical filter GF. Other, themeaning of the various symbols is as follows.

d0: The distance on-axis from aperture St to the object side surface ofthe first lens L1;

d1: The thickness on-axis of the first lens L1;

d2: The distance on-axis from the image side surface of the first lensL1 to the object side surface of the second lens L2;

d3: The thickness on-axis of the second lens L2;

d4: The distance on-axis from the image side surface of the second lensL2 to the object side surface of the third lens L3;

d5: The thickness on-axis of the third lens L3;

d6: The distance on-axis from the image side surface of the third lensL3 to the object side surface of the fourth lens L4;

d7: The thickness on-axis of the fourth lens L4;

d8: The distance on-axis from the image side surface of the fourth lensL4 to the object side surface of the optical filter GF;

d9: The thickness on-axis of the optical filter GF;

d10: The distance on-axis from the image side surface to the imagesurface of the optical filter GF;

nd1: The refractive power of the first lens L1;

nd2: The refractive power of the second lens L2;

nd3: The refractive power of the third lens L3;

nd4: The refractive power of the fourth lens L4;

ndg: The refractive power of the optical filter GF;

v1: The abbe number of the first lens L1;

v2: The abbe number of the second lens L2;

v3: The abbe number of the third lens L3;

v4: The abbe number of the fourth lens L4;

vg: The abbe number of the optical filter GF.

Table 3 shows the aspherical surface data of the camera optical lens 10in this embodiment of the present invention.

TABLE 3 Conic Index Aspherical Surface Index k A4 A6 A8 A10 A12 A14 A16R1 −1.3651E+02   2.8301E−01 −6.4209E−01 −3.1114E+00   1.1973E+01  3.2112E+00 −6.5753E+01   7.4060E+01 R2 −4.2440E+00 −4.1972E−01  8.1231E−01 −5.7263E−01 −2.1440E+00   5.0182E+00 −3.5534E+00  5.3833E−01 R3 −1.9089E+02   3.4425E−02 −5.4402E−01   1.8413E+00−1.9315E+00 −8.2833E−01   3.2918E+00 −1.7737E+00 R4   1.9372E−01−1.3747E−01 −7.9812E−02   4.3420E−01 −5.1821E−01 −3.1919E−01  1.1740E+00 −5.9153E−01 R5 −1.0383E+01   2.8293E−02 −3.0335E−02−2.2678E−01   3.7445E−01   2.9344E−02 −6.3678E−01   4.7308E−01 R6−8.0712E−01   3.5690E−01 −4.6833E−01   5.2630E−01 −3.7032E−01  9.4749E−02   2.4177E−02   6.4828E−03 R7 −1.0826E+01 −1.6207E−01−4.2215E−02   1.4934E−01 −1.5957E−01   9.4498E−02 −2.8179E−02  3.3086E−03 R8 −3.9435E+00 −1.8915E−01   1.2099E−01 −6.3003E−02  2.0335E−02 −3.7380E−03   3.3550E−04 −9.5155E−06

Table 4 and table 5 show the inflexion points and the arrest pointdesign data of the camera optical lens 10 lens in this embodiment of thepresent invention. In which, R1 and R2 represent respectively the objectside surface and image side surface of the first lens L1, R3 and R4represent respectively the object side surface and image side surface ofthe second lens L2, R5 and R6 represent respectively the object sidesurface and image side surface of the third lens L3, R7 and R8 representrespectively the object side surface and image side surface of thefourth lens L4. The data in the column named “inflexion point position”are the vertical distances from the inflexion points arranged on eachlens surface to the optic axis of the camera optical lens 10. The datain the column named “arrest point position” are the vertical distancesfrom the arrest points arranged on each lens surface to the optic axisof the camera optical lens 10.

TABLE 4 Inflexion point Inflexion point number Inflexion point position1 position 2 R1 1 0.405 R2 0 R3 2 0.385 0.435 R4 0 R5 1 0.855 R6 1 0.925R7 2 0.395 1.295 R8 1 0.485

TABLE 5 Arrest point number Arrest point position 1 R1 0 R2 0 R3 0 R4 0R5 0 R6 0 R7 1 0.775 R8 1 1.215

FIG. 2 and FIG. 3 show the longitudinal aberration and lateral colorschematic diagrams after light with a wavelength of 470 nm, 555 nm and650 nm passes the camera optical lens 10 in this embodiment. FIG. 4shows the field curvature and distortion schematic diagrams after lightpasses the camera optical lens 10 in this embodiment.

Table 6 shows the various values of the embodiment, and the valuescorresponding with the parameters which are already specified in theconditions.

As shown in Table 6, the embodiment satisfies the various conditions.

TABLE 6 Embodiment 1 0.7 < f1/f < 1.25 0.90679908 −2.5 < f2/f < −1.5−1.75668445 0.6 < f3/f < 1.1 0.83537051 −1.5 < f4/f < −0.7 −1.03055768TTL ≤ 3.6 mm 3.589 IH/TTL > 0.62 0.682641404

In this embodiment, the pupil entering diameter of the camera opticallens is 1.247 mm, the full vision field image height is 2.297 mm, thevision field angle in the diagonal direction is 84.00°.

It is to be understood, however, that even though numerouscharacteristics and advantages of the present exemplary embodiments havebeen set forth in the foregoing description, together with details ofthe structures and functions of the embodiments, the disclosure isillustrative only, and changes may be made in detail, especially inmatters of shape, size, and arrangement of is parts within theprinciples of the invention to the full extent indicated by the broadgeneral meaning of the terms where the appended claims are expressed.

What is claimed is:
 1. A camera optical lens comprising, from an objectside to an image side in sequence: a first lens having a positiverefractive power, a second lens having a negative refractive power, athird lens having a positive refractive power, and a fourth lens havinga negative refractive power; wherein the camera optical lens furthersatisfies the following conditions:0.7<f1/f<1.25;−2.5<f2/f<−1.5;0.60<f3/f<1.1;−1.5<f4/f<−0.7; where f: the focal length of the camera optical lens;f1: the focal length of the first lens; f3: the focal length of thethird lens; f4: the focal length of the fourth lens.
 2. The cameraoptical lens as described in claim 1, wherein the first lens is made ofplastic material, the second lens is made of plastic material, the thirdlens is made of plastic material, and the fourth lens is made of plasticmaterial.
 3. The camera optical lens as described in claim 1 furthersatisfying the following conditions:2≤f1≤5;−5≤f2≤−3;1.5≤f3≤3;−5≤f4≤−2; where f1: the focal length of the first lens; f2: the focallength of the second lens; f3: the focal length of the third lens; f4:the focal length of the fourth lens.
 4. The camera optical lens asdescribed in claim 1, further satisfying the following conditions:1.55≤n1≤1.65;1.6≤n2≤1.67;1.50≤n3≤1.55;1.6≤n4≤1.67; where n1: the refractive power of the first lens; n2: therefractive power of the second lens; n3: the refractive power of thethird lens; n4: the refractive power of the fourth lens.
 5. The cameraoptical lens as described in claim 1 further satisfying the followingcondition:IH/TTL>0.62; where IH: Image height; TTL: the total optical length ofthe camera optical lens.
 6. The camera optical lens as described inclaim 1, wherein the total optical length TTL of the camera optical lensis less than or equal to 3.6 mm.